Class Bivalvia Linnaeus, 1758 - bivalves Subclass Autobranchia Grobben, 1894 Superorder Heteroconchia Gray, 1854 Clade Heterodonta Neumayr, 1884 Superfamily Gastrochaenoidea Gray, 1840 [monotypic] 1 Family Gastrochaenidae Gray, 1840 - rock borers